{
	{(0, a), (1, a)},
	{(0, a), (1, b)},
	{(0, a), (1, c)},
	{(0, a), (1, d)},

	{(0, b), (1, a)},
	{(0, b), (1, b)},
	{(0, b), (1, c)},
	{(0, b), (1, d)},

	{(0, c), (1, a)},
	{(0, c), (1, b)},
	{(0, c), (1, c)},
	{(0, c), (1, d)},

	{(0, d), (1, a)},
	{(0, d), (1, b)},
	{(0, d), (1, c)},
	{(0, d), (1, d)}
}